At least 11 children have reportedly been killed in a NATO airstrike in Kunar province in eastern Afghanistan.
The children were killed during a joint Afghan-NATO operation against Taliban fighters in the Shigal district of restive Kunar province bordering Pakistan late on Saturday, according to Hamid Karzai, the Afghan president.
Karzai "strongly condemned the ISAF air strike in Kunar that killed 11 children", in a statement issued by his office.
"The president, while condemning the use of civilians as shields by the Taliban, denounced any kind of operations that cause civilian deaths," the statement said.
The president has also ordered a government investigation into the killings.
There were conflicting figures of the death toll, but Karzai's office later said 11 people were killed - all of them children - and six women were wounded.
| Our complete Afghanistan coverage
Wasifullah Wasifi, the spokesman for the Kunar governor, confirmed the attack to Al Jazeera.
"We confirm a raid done by Afghanistan's intelligence service in the district of Shigal. In this raid, the security forces killed 20 Taliban in which 10 of them are very senior Taliban members," he told Al Jazeera.
The interior ministry said in a statement the attack by coalition forces killed six Taliban including two senior commanders.
A spokesman for NATO's International Security Assistance Force (ISAF) confirmed the strike and said the coalition was gathering information to determine what happened.
A UN report in February said that the Taliban and other anti-government groups were responsible for 81 percent of all civilian deaths in Afghanistan last year.
Overall civilian deaths were down in 2012, but the UN says targeted killings of government employees were up 700 percent.
And attacks on women and children, particularly those working or going to school, was up 20 percent.
Al Jazeera's Imtiaz Tyab, reporting from the capital, Kabul, said that joint forces entered houses in Shigal village in the early hours of Sunday and carried out raids in addition to the air strikes.
"Al Jazeera has contacted NATO. We were told by a spokesperson that they were aware of the operation and that they have heard of some civilians who may have been injured in this strike," our correspondent said.
Captain Luca Carniel, an ISAF spokesman, said ISAF had provided air support during the operation, but he said there had been no ISAF troops on the ground. The air strike had been requested by coalition forces, not their Afghan allies, he said.
Civilian deaths have been one of the most contentious issues in the 11-year campaign against Taliban fighters, provoking harsh criticism from the Afghan president and angry public protests.
After an air strike killed 10 civilians, mostly women and children, in February, Karzai banned Afghan security forces from calling in NATO air strikes.
The latest strike came a day after at least five Americans, including a young female diplomat, were killed in two Taliban attacks in the country's east and south.
A suicide car bomber struck a NATO convoy in the southern province of Zabul on Saturday, killing three US soldiers and two civilians, one of whom was a female US diplomat.